nifkyfandomcom-20200214-history
IPT
Definitions of words *'Arranging' - Ordering the data in some specific and intentional way. It refers to the way the data is structured, not just how it's sorted. *'ASCII' - American standard code for information interchange *'Context diagram' - A systems modelling technique describing the data entering and leaving together with its source and sink. *'Data flow' - A labelled arrow on context and data flow diagrams describing the nature and direction of data movement. *'Data integrity' - Occurs when data is correct and accurately reflects its source (the quality of the data). *'Data validation' - A check, at the time of data collection, to ensure the data is reasonable and meets certain criteria. *'Data verification' - A check to ensure the data matches the source of the data. *'EBCDIC' - Extended Binary Coded Decimal Interchange Code. *'Environment' - the circumstances and conditions that surround an information system; everything that influences or is influenced by the system. *'Group information system' - An information system with a number of participants who work together to achieve the system's purpose. They often operate with the assistance of a computer network, this helps participants to share data and work together more effectively as a team. *'Indirect users' - Often a source of data or receive information from the system without actually being involved in it. They are in the system's environment. *'Information' - The meaning that a human assigns to data. Knowledge is acquired when information is received to people. *'Information processes' - What needs to be done to transform the data into useful information. These actions coordinate and direct the system's resources to achieve the system's purpose. *'Information system' - A system whose primary purpose is to process data into information. The data is collected; processed using various resources of the system and finally the resulting information is output. *'Information technology' - The hardware and software used by an information system to carry out its information processes. data and information are various forms of information technology. *'Knowledge' - see a few headings below *'Participants' - People who carry out or initiate information processes within an information system. An integral part of the system during information processing. Compare with users. *'Personal information system' - an information system with a single participant who is also the sole end user. The processes occurring withing this system are performed by this person (such as the seven information processes). During these processes no one else is directly involved; this computer may or may not be on a network, however all the processes are initiated and performed using this single machine by a single person. Examples of them are word and excel, and non-computerized ones are diaries, address books, income tax records and motor log vehicle logbooks. *'Purpose' - The aim or objective of the system and the reason the system exists. The purpose fulfills the needs of those for whom the system is created (the users). When developing new information systems the purpose is used as the basis for developing a series of definite and achievable requirements. *'Representing' - Each data item must be coded so that it can be understood and used efficiently by other information methods to symbolise/represent the data. *'Sink' - An external entity that is the recipient of output from an information system. *'Source' - An external entity that provides data (input) to an information system. *'Storage' - a place where data is stored for later use *'System' - Any organised assembly of resources and processes united and regulated by interaction or interdependence to achieve a common purpose. It is a collection of sub-systems that work together. * Systems flowchart - A systems modelling technique describing the logic and flow of data, together with the genera; nature of the hardware tools. *'Technology' - The result of scientific knowledge applied to practical problems. *'Users' - People who use the information produced by an information system either directly (direct users) or indirectly (indirect users). An information system exists to provide information to its users. Examples of things *'Systems' - e.g. a braking system where the driver applies pressure to the brake pedal, which causes fluid to move from the master cylinder to a calliper, where the fluid pressure causes the brake pads to push against the brake disk causing friction which then slows down the wheel's rotation. Because the tyres are gripping the road surface the reduction in rotation speed also slows down the road speed. Determining the purpose of the information system with the steps below #Identify the people whose needs the information system should meet. #Formulate a list of needs the information system should realise. #Translate these needs into objectives that form the system's purpose. Important notes *'Almost all systems are themselves made up of smaller sub-systems and similarly almost all systems are part of larger systems. Everything that influences or is influenced by the systems is said to be in the environment.' *'A system has a purpose and an environment. Notice that the system's purpose is achieved outside the system but within the environment.' *'There are many methods of presenting systems diagrammatically, e.g. context diagrams, data flow diagrams and system flowcharts .' (examples in definitions) *'Processes and resources are a part of a system, which is in the environment which contains the purpose. The environment contains all its various sub systems.' *'Information needs to knowledge.' *'Participants = resources used by the system (integral and actual operation of the system). Hence indirect users and developers (development personnel) are not considered participants in the system.' *'E.g.: a customer in a shop is an indirect user of the cash register system.' *'When computer technology is used most personal information systems operate using a single personal computer. During these processes no one else is directly involved; this computer may or may not be on a network, however all the processes are initiated and performed using this single machine by a single person. They mostly use word processing and spreadsheet applications. These two files do not generally allow a file to be edited simultaneously on more than one machine. Non-computerized examples are diaries, address books, income tax records and motor log vehicle logbooks.' *'Data entry operators are primarily involved in collecting, managers are more involved analyzing the data, there are also people in a group information system that are not participants - e.g. technical personnel and network engineers who ensure the computer network functions correctly and securely.' *'Data validation ensures the data is reasonable and is in the correct format while data integrity is ensuring that it is correct.' *'Context diagrams show data movements between the system and the environment.' *'Dataflow diagrams describe data connections between the system and the environment.' *'The seven information methods are present in most information systems.' *'Collecting the same data multiple times should be restricted to crucial data.' Comparison between information, data and knowledge Generally Data + information = information which then can be used as knowledge. *It is not until these facts are understood and meaning derived that we have information. For example, Data is '123456.65', information is 'your savings account balance is $123,456.65' and knowledge is 'I've got enough money to buy that Ferrari'. Input devices *Virtual keyboard *Graphics tablet *Mouse *Keyboard (Qwerty, Dvorak, numeric keypad) *Flatbed scanners to 'digitalise' analog images/text, not a barcode reader *Joystick *Touchpad *Touchscreen *Gaming console *Barcode reader, not a flatbed scanner *Digital cameras, i.e. video or still Output devices *Monitor/visual display unit: ::LCD - ::CRT ::Plasma *Storage devices: ::USBs *Printers: ::Laser ::Ink-Jet ::Thermal (receipts; low-quality, cheap, paper reacts to heat to form 'text', ink fades with heat over time) ::*Plotter: :::Drum plotter for hospital patients :::Flatbed plotter for architects Diagram of an information system *Environment :Purpose :Information system ::Information processes ::Resources :::Participants :::Data/information :::Information technology Data is exchanged from the purpose and information processes, and processes and sub-resources of resources. Relationships between information processes *External entity (inputs data). This is the source which may be an indirect user, a communication link, etc.; it is external to the system. *This goes to the information system which has information processes inside it) *This then goes to the external entity (sink) which has the output (information) An information system can have multiple sources and multiple sinks; it is common for a single entity to be both a source and sink. Seven information processes #Collecting #::::o Surveys (paper-based) #::::o Questionnaires (paper-based) #::::o Interviews #::::o Online #:::• Closed questions #::::o Easy to analyse eg. Multiple choice (T/F, Y/N are Boolean responses) #::::o Likert scale (SD-D-N-A-SA) #::::o Difficult to get qualitative data (can't get answers as to why) #:::• Open questions #::::o Difficult to analyse #::::o Allow for a range of responses #::::o Qualitative and not quantitative Steps needed: *Define the data - what is needed? This needs analysis. *Identify the source of the data. Factors needed to be considered are availability, cost, and validity/integrity. *This data then needs to be gathered - that is input methods have to be used to take down the data. #Analysing ::•Taking collected/organised data and creating information (searching, sorting, comparing, predicting (What if? Analysis), Graphing)) :::e.g. Searching for clients who have not made a purchase in the past 3 months. #Transmitting and receiving - parallel buses/cables (cables up to 5m) compared to serial (optical fibres for internet) (more used nowadays and better) #Displaying - e.g. printer, monitor #Organising - how the same data is presented in a different format that it can be represented, structured and efficiently analysed. ::::This needs to be arranged - e.g. in a database for text, spreadsheet for words ::::Then represented. - e.g. using combinations of letters to represent symbols or words. #Storing and retrieving ::•Primary storage – eg. RAM (volatile) & ROM (non-volatile) ROM can be changed without energy to maintain it, while RAM does ::•Secondary storage – eg. USBs, HDD, CD, DVD :::Without this ability it would not be possible to reuse data without it being continuously entered. #Processing :::Manipulating by updating or editing. Alters existing data. CPU is continually doing this with binary ones and zeros. :::Examples is changing students years' at the end of the school year to the next subsequent one. Data entry methods •DCR – optical character recognition – eg. Lottery forms, enrolment forms, open response fields with individual boxes for each letter – 90% accurate – characters can be read wrong •Check boxes, shading circles etc. for closed responses – eg. Multiple choice tests – 98-99% accurate although a rubber may not rub out a response entirely or two boxes are marked •Data entry operator – a person whose job is to interpret paper-based data and manually enter the data into a computer system This is how data is electronically put into an information system. Participants Users *Direct users - e.g. managers, direct users, data entry operators *Indirect users They are not participants. Classification of information systems *Personal information systems *Group information systems Social and ethical issues *Privacy of the individual :Privacy in Australia is legally protected by the Privacy Act 1988, the information systems have to say why, how, where is the information stored/managed. They also must be legally able to provide individuals with access to their records, correct inaccurate information, and divulge details of other organisations who are given information from that system. *Security of data and information *Accuracy of data and information *Changing nature of work - becoming more 'computerised' *Appropriate information use *Health and safety - hours in front of a computer screen, concerns the total work experience. ::Covered by the Occupational Health and Safety Act 2000 and Occupational Health and Safety Regulation 2001. ::Ergonomic furniture, hardware design and placement must be appropriate ::Lighting should be appropriate and not cause glare. ::Noise levels should be reasonable. Work routine should not be boring and uncomfortable (working continuously on the same task may cause RSI) ::Software design should be well suited by the user to work with. ::Carpal tunnel syndrome - employers can be sued for for not providing adequate provisions in the work place (computer workstations) *Copyright laws - covered by the Copyright Act 1968 which continues for the life of the author + 50 years. ::It protects the way in which the idea is expressed rather than the ideas or information within the work. The copyright symbol, author's name and publication date is not needed but is recommended to help others establish the owner of a work's copyrights. All works are automatically covered by copyright law unless the author specifically relinquishes it. ::In regards to software only one copy of the software may be made for backup purposes. Possible security risks of data and information *Virus attacks *Hackers *Theft - unauthorised copying of data *Unauthorised access by past and present employees *Hardware faults *Software faults Strategies used to circumvent them *Passwords *Backup copies *Physical barriers *Anti-virus software *Firewalls *Data encryption *Audit trails (maintaining records of all transactions) Inappropriate use of information systems *Unauthorised access, alteration or destruction of another user's data, programs, electronic mail or voice mail. *Attempts to obtain unauthorised access to either local or remote computer systems or networks. *Attempts to circumvent established security procedures or to obtain access privileges to which the user is not entitled. *Attempts to modify computer systems or software in any unauthorised manner. *Unauthorised use of computing resources for private purposes. *Transmitting unsolicited material such as repetitive mass mailings, advertising or chain messages. *Release of confidential information. *Unauthorised release of information. Storage processes Context diagrams Diagram of a CPU Diagram of processes Garbage in/out principle “It doesn't matter how well you organise/analyse data, if the originally collected data is unreliable or inaccurate, so will be the results.” This is significant towards the accuracy of data and information. Data entry in application software Refer to definitions. Why information technology uses digital data *Similar hardware design *Ability to use different types of media *Efficient data transfer *Storage of data *Speed and accuracy of processing Disadvantages *Not human friendly *Accuracy *Cost *Security *Training Types of media *Text - e.g. ASCII or EBCDIC. There is no tab indent in ASCII. ::EBCDIC: The letters are identical until number 127 in both text based codes. There are codes for start underline and end underline encasing the word in between them. *Numbers - computers use base 2/binary ::Real numbers, floating point: it's a technique similar to scientific notation ::There are usually two decimals in currency. *Images ::Bitmap is stored in binary ::Pixels stand for picture element. 1440 by 900 (horizontal and vertical pixels) ::Picture file size - number of horizontal by number of vertical pixels by number of bits per pixel ::1 bit/pixel 21 ::2 bits/pixel 22 ::8 bits/pixel 28 ::16 bits/pixel – TV screen - PAL ::32 bits/pixel – high resolution TV screen ::A black and white image uses 1 for black and 0 for white. ::The concept that a certain number of bits are pixels are the screen is called bit-mapping; the higher the amount of bits per pixel, ::the higher the resolution of the image. ::A locus is a term to describe any curved complex shape, e.g. in a vector image. *Audio - sampling ::Analog (what we hear) ::Digital (in the computer) in binary notation How do we make an analogue signal digital? (0,1), (1,2), (2, 4).. – sampling of ordered pairs on a plotted graph with a x and y axis in a straight line. ::MP3 is compressed *Video - MP4 is compressed, others aren't Scale in terms of size big to small: Video > sound > graphics > text What are the first things to the received on a webpage? 1. Text 2. Background image 3. Basic graphics :a. Vector :b. Bitmaps 4. Sound 5. Video - Video is a continuous playback of images, at least 30 per second. Frequency determines the volume and amplitude the pitch. Operating systems/interfaces *Operating system (OS) :• MS DOS (Microsoft Disk Operating System). Command prompt driven. :• Graphical User Interface (GUI) ::Features: Windows Icons Mouse Pointer (WIMP) *Examples: Apple Mac OS, Windows 95 (first successful MS GUI) :In 2003 Windows XP came out :2009 – Windows 7 *Classification of computer systems - simple dedicated microprocessors that can be found in your watch, calculator, car and big machines maintained by banks Software • Office – Word processing, database, spreadsheet • Games – high level graphics, interactive, modelling/simulation • Web browsers – Email, browsing • Graphics –Still images, convenience and cheapness, editing with Photoshop, o video images, uses a lot of memory (30 frames per second), home video can be made: editing programs are Adobe Premier , Windows Movie Maker • Utilities – Software that is not essential but performs important system functions. o E.g. Virus checker o Disk Utilities/Disk Cleanup o Disk defragmenter o Disability support • Custom o Software written for a specific task and industry • Utilities – Software that is not essential but performs important system functions. o E.g. Virus checker o Disk Utilities/Disk Cleanup o Disk defragmenter o Disability support Audio (sound) from poor to excellent -System speaker (basic) – MONO. Has BIOS beeping, beeps when something is wrong e.g. holding down a key for a while for on startup -External speakers (advanced) – STEREO (left/right channel, 2 channels) -quadraphonic left/right/front/back -Dolby (5.1 surround sound) Subwoofer makes the ground shake with low frequency vibrations Storage -tape -Magnetic material ∙very cheap ∙very slow, sequential access data -VCR -RAM ->Random access memory -Disks ∙Circle shape faster than a long rectangular shape ∙All points on the disk can be accessed with one revolution ∙When a disk is formatted, the computer divides the disc into concentric circles called ‘tracks’ and also along its radius into sectors. Each of these small areas can store data. ∙Uses a system called FAT (Fat Allocation Table). Data can be fragmented on the disc. Hardware Buses are those long things that are thick. They send information throughout the system and vary is thickness and colour. They have a red stripe at one end to show how to put it in the hard disk/floppy disk/DVD drive. Hard disks, floppy disks, and DVD drives have a power source and a port for a bus (which are the same). Difference between CCDs and LEDs " The important difference between a CCD reader and a pen or laser scanner is that the CCD reader is measuring emitted ambient light from the bar code whereas pen or laser scanners are measuring reflected light of a specific frequency originating from the scanner itself." - Wikipedia CCD overview Charged coupled devices contain one or more rows of photocells built into a single microchip. Used in cameras, barcode scanners, digital and video cameras, flatbed scanners and handheld image scanners. For both barcode and image scanners a single row CCD is used. The light source for these scanners is typically a single row of LEDs with the light being reflected off a mirror. The mirror reflects the light onto a lens that focuses the image at the CCD. Each photocell in the CCD transforms the light into different levels of electrical current. These currents are converted into bits using a similar techinique to that used in LED and laser barcode scanners. Flatbed scanners differ slightly; they convert the electrical current from each photocell into a binary number, normally between 0 (black) to 255 (white) using a more complex analog to digital converter (ADC). *CCDs in analog and digital recorders and microphones convert light and sound waves into electrical current. Vehicle counting and monitoring *Air pressure based vehicle counter with air pressure switch *An induction loop on the road's surface *Safe-T-Cam Data entry into application software *Data integrity - high quality data has high levels of data intergrity. It is whent he data is correct and accurately reflects its source. *Data validation - when the data is reasonable and meets certain criteria. *Data verification - to ensure the data collected matches the source of the data. Social and ethical issues Inefficiencies of data collection *Usually the cheapest or most available source of data is used rather than the best source of data *Internet users are not a representative sample of the population - they are younger, have higher incomes and have higher technology skills than the general population. Failure to acknowledge the source of data *Laws ask people to *Apart from copyright, some of the reasons for acknowledging sources of data are justification of outputs, providing a mechanism for tracking and auditing data and requirement of the source organisation. Privacy concerns of individuals *Must be fair and lawful *Participants must be informed why *Information is best taken directly from the individual rather than from a company that the person may not be informed of *Sensitive personal information must not be collected without individuals giving their specific consent. Ergonomics for data participants *Rest breaks of 5 - 10 mins every hour and 8 hour shifts each day maximum. *Allow the data entry operator the ability to change their physical position regularly and to design tasks that do not require repetitive actions for a significant amounts of time. *Operator should have the freedom to complete their tasks in an order that best suits their needs. *Think about the layout of the workstation and how it is positioned